Not Applicable.
1. Field of the Invention
The present invention relates to a golf club head composed of a composite material. More specifically, the present invention relates to a golf club head composed of composite material and designed to have an enhanced sound when impacting a golf ball.
2. Description of the Related Art
When a golf club head strikes a golf ball, large impacts are produced that load the club head face and the golf ball. Most of the energy is transferred from the head to the golf ball, however, some energy is lost as a result of the collision. The golf ball is typically composed of polymer cover materials (such as ionomers) surrounding a rubber-like core. These softer polymer materials having damping (loss) properties that are strain and strain rate dependent which are on the order of 10-100 times larger than the damping properties of a club striking plate.
Golfers have become accustomed to hearing a particular sound when the club face impacts the golf ball, especially when a driver or fairway wood is used by the golfer. This xe2x80x9csound expectationxe2x80x9d has grown tremendously since the introduction of hollow metal woods. This particular sound imparts a sensation to the golfer of a good shot, a quality club or both.
The sound expectation from a metal wood has become so entrenched that woods lacking this particular sound are believed to be inferior or are undesired by golfers. This sound expectation has greatly effected composite golf clubs since current composite golf clubs have an undesirable xe2x80x9cthudxe2x80x9d sound, reminiscent of persimmon woods.
Further, the current manufacturers of composite golf clubs have had no desire to improve the sound since improving the performance and lowering the costs of the composite golf clubs have been the major design concerns of such manufacturers. Thus, although the performance and price of composite golf clubs have improved, the sound has remained unchanged and is an obstacle to increased acceptance of composite golf clubs.
The present invention provides a composite golf club head that has a predetermined sound during impact with a golf ball. The present invention is able to accomplish this by designing the composite golf club head in a particular shape and orienting the plies of pre-preg composite sheets to enhance the sound during impact with a golf ball.
One aspect of the present invention is a golf club head having a body composed of a composite material and having a combined sound level greater than one hundred seventeen decibels during impact with a golf ball. The golf club head also has a coefficient of restitution of at least 0.83 under test conditions, such as those specified by the USGA. The standard USGA conditions for measuring the coefficient of restitution is set forth in the USGA Procedure for Measuring the Velocity Ratio of a Club Head for Conformance to Rule 4-1e, Appendix II Revision I, Aug. 4, 1998 and Revision 0, Jul. 6, 1998, available from the USGA.
Another aspect of the present invention is a composite golf club head having a body, a weight strip and a sole plate. The body has a hollow interior and is composed of a plurality of plies of pre-preg sheets. The body has a striking plate, a sole, a crown, a ribbon juxtaposed by the sole and the crown, a heel end and a toe end. The weight strip is disposed on the ribbon. The sole plate has an integral hosel tube and is attached to the sole with the integral hosel tube disposed in the hollow interior. The composite golf club head has a combined sound level greater than one hundred seventeen decibels during impact with a golf ball when measured from a distance of sixty-four inches from the impact point.
Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings.